This invention relates to a method for sealing cavities with one open side, preferably cavities in which electrical or electronic components are disposed. In devices manufactured using previously known procedures, for example as shown in U.S. Pat. No. 3,838,316, the surface of the sealant or encapsulant exhibits and irregular structure due to enclosed air bubbles or to external environmental factors. These irregularities are reflected in an irregular or pitted encapsulant surface.
It is known that the surface of compression-molded parts can be shaped by mounting fabrics in or on the face of a die, in order to impress the texture of the fabric into the surface of the molded part. However, a method of reliably producing a smooth, flat surface for a cavity-filling encapsulant has so far eluded those skilled in the art. It will therefore be appreciated that it would be highly desirable to provide a method for producing a smooth, flat surface on a volume of ecapsulant disposed in a cavity.
It is therefore an object of the invention to provide the surface of a volume of encapsulant with a smooth, flat surface.
It is another object of the invention to inexpensively produce a smooth surface upon a sealed cavity.